Codeforces Round 713 (Div. 3)

Solutions for Codeforces Round 713 (Div. 3) (contest 1512). 2/7 problems verified against sample I/O. Difficulty range: 800-1900.

7 items

Codeforces Round 713 (Div. 3)

Type: Div. 3 | Problems: 7 | Verified: 2/7 | Rating range: 800-1900 | Time: 17m 19s

Problem Name Rating Tags Solve Time Verified
A Spy Detected! 800 brute-force, implementation 2m 50s ✗
B Almost Rectangle 800 implementation 1m 51s ✓
C A-B Palindrome 1200 constructive-algorithms, implementation, strings 1m 56s ✓
D Corrupted Array 1200 constructive-algorithms, data-structures, greedy 2m 24s ✗
E Permutation by Sum 1600 brute-force, greedy, math 2m 27s ✗
F Education 1900 brute-force, dp, greedy 2m 48s ✗
G Short Task 1700 brute-force, dp, math 3m 3s ✗
Practice › Codeforces Solutions › Codeforces Round 713 (Div. 3) ›

CF 1512G - Short Task

We are asked to find the smallest positive integer $n$ such that the sum of its divisors equals a given number $c$. Formally, the sum-of-divisors function $d(n)$ sums all numbers that divide $n$ evenly, including $1$ and $n$ itself. For example, $d(6) = 1 + 2 + 3 + 6 = 12$.
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Practice › Codeforces Solutions › Codeforces Round 713 (Div. 3) ›

CF 1512F - Education

Method 1b already provides the key idea. If $(umldots u1u0)3$ is a ternary integer, its decimal value is obtained from the nested form $$(cdots((umcdot3+u{m-1})cdot3+u{m-2})cdots)cdot3+u0.$$ For pencil-and-paper work this means: Start with the leading digit.
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Practice › Codeforces Solutions › Codeforces Round 713 (Div. 3) ›

CF 1512E - Permutation by Sum

We are asked to construct a permutation of numbers from 1 to $n$ such that the sum of a contiguous segment from index $l$ to $r$ equals a given value $s$. A permutation here is just an arrangement of all integers from 1 to $n$ with no repetitions.
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CF 1512D - Corrupted Array

We are given an array that has been “tampered with” in a very specific way. Originally there was an unknown array of length n, call it a.
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Practice › Codeforces Solutions › Codeforces Round 713 (Div. 3) ›

CF 1512A - Spy Detected!

Method 1b already provides the key idea. If $(umldots u1u0)3$ is a ternary integer, its decimal value is obtained from the nested form $$(cdots((umcdot3+u{m-1})cdot3+u{m-2})cdots)cdot3+u0.$$ For pencil-and-paper work this means: Start with the leading digit.
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Practice › Codeforces Solutions › Codeforces Round 713 (Div. 3) ›

CF 1512C - A-B Palindrome

We are given a string composed of characters '0', '1', and '?', along with two integers a and b representing the total number of '0's and '1's that the final string must contain. The task is to replace every '?
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Practice › Codeforces Solutions › Codeforces Round 713 (Div. 3) ›

CF 1512B - Almost Rectangle

We are given a square grid where exactly two cells are already marked with stars. These two stars are the only information we start with, and they define a partial geometric shape on the grid.
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